| Project/Area Number |
16390306
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Pediatrics
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| Research Institution | JICHI MEDICAL UNIVERSITY |
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Principal Investigator |
KUME Akihiro Jichi Medical University, School of Medicine, Associate Professor, 医学部, 助教授 (10264293)
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| Co-Investigator(Kenkyū-buntansha) |
OZAWA Keiya Jichi Medical University, School of Medicine, Professor, 医学部, 教授 (30137707)
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| Project Period (FY) |
2004 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥12,700,000 (Direct Cost: ¥12,700,000)
Fiscal Year 2006: ¥4,100,000 (Direct Cost: ¥4,100,000)
Fiscal Year 2005: ¥4,100,000 (Direct Cost: ¥4,100,000)
Fiscal Year 2004: ¥4,500,000 (Direct Cost: ¥4,500,000)
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| Keywords | gene therapy / transplantation / chronic granulomatous disease / cell and tissue / translational research / 造血微小環境 / 骨髄腔内注入法 / 選択的増幅遺伝子 / 造血幹細胞 / エリスロポチエン受容体 / 顆粒球コロニー増殖因子受容体 / 慢性肉弾腫症 / 浩血微小環境 / 選択的増幅潰伝子 / 浩血幹細胞 / エリスロポエチン受容体 |
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| Research Abstract |
To improve the efficacy of hematopoietic stem cell gene therapy, selective amplifier genes (SAGs) were refined. SAGs are artificial genes encoding chimeric receptors comprising growth factor receptors and the extracellular domain of erythropoietin (Epo) receptor. Such fusion molecules generate growth signal when activated by Epo, and all the components were derived from human proteins. After confirming the fact that the refined SAGs functioned as cell growth switch in vitro, we chose the best SAG to further clarify its in vivo efficacy in the mouse model of X-linked chronic granulomatous disease (X-CGD). Bone marrow cells from donor X-CGD mice were transduced with a retrovirus vector carrying the SAG and the gp91-phox gene, the therapeutic gene for X-CGD, and transfused to X-CGD recipients. The first round Epo administration resulted in a significant increase of functionally corrected neutrophils in the recipients (from 1.0±0.1% to 3.9±0.8%; p=0.006), and the second round Epo administr
… More
ation lead brought up a similar increase (from 1.5±1.1% to 3.9±0.8%; p=0.065). The result demonstrated that the Epo-responsive SAG product reinforced the efficacy of stem cell gene therapy. Preclinical studies of the SAG system with non-human primates are to be launched.
The efficacy of intra-bone marrow transplantation (iBMT) was investigated in the X-CGD mouse model. This method allows very small number of hematopoietic stem cells to engraft otherwise rejected. Reduced intensity preconditioning is preferable in stem cell transplantation and gene therapy for X-CGD, to minimize procedure-associated risks. When more than 10^6 wild type bone marrow cells were transplanted through either intravenous infusion or iBMT, donor cells engrafted in X-CGD recipients given a low-dose irradiation (4 Gy). However only iBMT allowed wild type cells to engraft when the number of donor cells were smaller than 10^6.
Mesnchimal stem cells (MSCs) give rise to various lineages of cells including bone marrow stromal cells displaying the hematopoietic niche. We investigated the difference between MSC-like 10T1/2 cells and their preadipocyte-like derivative A54 cells. A54 cells overexpressed cytokines such as Steel factor, CXCL12 and Ang-1 which were further upregulated upon treatment of a myeloid cell-derived cytokine. In accordance with this upregulation, cobblestone and colony formation by cocultured hematopoietic stem/progenitor cells was augmented. The result suggested that cotransplantation of MSCs would support the engraftment of hematopoic stem cells. Less
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